Steam superheater



Oct. 1, 1929; T. MART STEAM SUPERHEATER Filed Oct. 9, 1924 2Sheets-Shpet l Oct. 1, 1929. 1,729,837

1.. T. MART STEAM SUPERHEATER Filed Oct. 9, 1924 2 Sheets-Sheet 2Patented Oct. 1, 1929 UNITED STATES LEON T. MART, OF KANSAS CITY,

MISSOURI STEAM SUPERI-IEATER Application filed October 9, 1924. SerialMy invention relates to steam superheaters, with particular reference tosuperheaters for use with return tubular boilers, or other shellboilers.

A purpose of my invention is to support a steam superheater upon theopposite side walls beneath an arch, shown in the drawings as the reararch of a return tubular boiler.

A further purpose is to support an arch of a return tubular boiler uponthe horizontally spaced headers of a superheater.

A further purpose is to avoid the use of return bends or castings withinthe fire zone.

A further purpose is to provide a superheater with an advantageous formof interchangeable headers.

A further purpose is to connect horizontally spaced headers having inletand outlet re spectively of a superheater by a plurality of straighttubes through the heating zone and to internally baffle the headers toform a three-pass superheater unit in which the steam has to pass threetimes across the heating space between the inlet and outlet.

Further purposes will appear in the specification and in the claims. A

I have preferred to illustrate my invention in one main form only (witha slight modification) of the various forms it may take,

selecting a form that is inexpensive and effective in operation andwhich illustrates particularly well the principles involved.

Figure 1 is a perspective View illustrating the preferred form ofsuperheater unit.

Figure 2 isa somewhat diagrammatic side elevation showing a returntubular boiler equipped with my superheater.

Figure 3 is a fragmentary section of Figure 2,.to enlarged scale, takenupon the line 33.

Figure 4 is a fragmentary top plan view of Figure 3.

Figure 5 is a fragmentary section of Figure 4 4L taken upon the line55..

Figure 6 is a reducedperspective view of a slightly modified form.

In all figures like numerals refer to like parts.

Describing in illustration and not in limitation and referringto thedrawings Prior to my invention steam superheaters for shell boilershaveusually extended down through the rear archthat farther from thestackand into the relatively intense heat of the zone. Thus placed theyhave been subjected at the lower end to excessive temperathem. This alsoenables me to support the rear arch upon the horizontally spaced headersof the super-heater. The heating tubes are out of the way, not subjecttothe too intense heat of the fire zone, and readily accessible forinspection or renewal. Thus installed the superheater makes it mucheasier to install and to maintain the rear arch.

The. superheater unit comprises horizontally spaced headers 6and 6preferably alike and interchangeable They are connected by straighttubes 7, and each is provided with a flanged opening 8 for steamconnection, the inlet for the piping shown being uponone side and theoutlet upon the other of the top of the unit formed, the inlet in oneheader and the outlet in the other.

The headers, which may be of cast metal. are-shown as partitioned, as at9 to make the unit three pass, that is to cause the steam to pass athigh velocity three times through the heating zone of the (rear) flue10.

In Figure 6 there is a slight modification in that inlet and outlet arefrom the same header. There is one partition in this header but none inthe other, so as to make this a.

outside heating flue 15, rear uptake 10, fire tubes 16, stack uptake 17,stack 18, and main steam pipe 19. 1

The superheater unit horizontally span the rear flue 1O slightly beneaththe flue cover or rear arch 20, one header, as 6, resting horizontallyalong the side wall 21 of the flue 10 and having flange connection at 22with the steam pipe 19 from the boiler, and the other header, as 6,resting upon the opposite side wall 23 of the flue and discharging atany convenient point 24: into the superheated steam supply line 25. Thesuperheating surfaces are provided by the tubes 7 between the headers.

The rear arch 20 is shown as comprising bricks or tiles 26 which aresupported by transverse angles 27 and T 28 which angles and T are inturn supported at their ends by resting on the respective headers 6 and6'.

It will be noted that all cast port-ions of the unit are placed outsidethe intense heat of the flue, the heating surface being straight lengthsof worked metal in the form. of the pipes between the headers. This isan obvious advantage as they can stand intense heat well.

It will further be noted that the covered arch reflects heat upon thetubes which carry the steam so that without necessity for excessive heatat any point it is possible to obtain very uniform heat upon the bottom,top and sides of the tubes.

Steam materially expands during its passage through the superheater unitso that when the header units are alike the discharge velocity isconsiderably greater than the velocity of intake. For this reason it maysometimes be deemed preferable to forego the advantage of having theheaders alike, proportioning the headers and connecting pipes to securea more uniform velocity throughout the unit.

Likewise it may sometimes be deemed preferable to forego the advantageof the three pass arrangement obtained by providing a partition 9 ineach header, and in this event these partitions may be dispensed with.While the three pass arrangement is desirable in that it gives moreintense superheating it has also the disadvantage of giving more loss inpressure through the unit which under some conditions may make thesingle pass arrangement preferable.

In view of my invention and disclosure variations and modifications to,meet individual whim or particular need to secure all or a part of thebenefit of my invention are likely to become evident to others skilledin the art and I therefore claim all such in so far as they fall withinthe reasonable spirit and scope of my invention.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is 1. In a steam superheater and boiler unit, afire tubular boiler, side walls forming a flue leading to the boilertubes, a superheater comprising steam headers supported upon the sidewalls and steam tubes connected with the headers across the upper partof the flue, and roofing for the flue above the steam tubes and close tothem.

2. In a steam superheater and boiler unit, a fire tubular boiler, sidewalls forming a flue leading to the boiler tubes, a superheatercomprising steam headers supported upon the side walls and steam tubesconnected with the headers across the upper part of the flue, androofing for the flue supported upon "the headers and raised above thetubes to provide passage for flue gases about the steam tubes.

3. In a steam superheater and boiler unit, a hot flue having opposingwalls, a pair of horizontally spaced steam headers in line with thewalls, having the length of the headers horizontal and the long sides ofthe headers forming the tops and bottoms of the headers, pipes makingcounterconnection across the flue between the headers, an arch supportedfrom the headers free from the pipes, steam inlet and outlet connectionto the headers and a fire tube boiler arranged with its tubes in theimmediate path of the hot gases passing the steam tubes.

4. In the equipment for a return tubular boiler, a flue at one end ofthe boiler opening into the tubes thereof and having opposing walls, aheader upon each wall, pipes in the flue making a conduit unit with theheaders, cover supports carried by the headers, a cover upon thesupports free from the pipes, a steam inlet at one end of the unit and asteam outlet at the other end.

5. In a superheater for return tubular boilers, a flue at one end of theboiler, opening into the tubes thereof and having opposite I walls, aheader upon each wall, a plurality of rows of pipes across from headerto header and staggered, one row with respect to the other,arch-supports resting upon the headers above the pipes and an arch uponthe supports giving room for circulation between and about the pipes.

6. A pair of sidewalls, steam superheater headers supported upon thesidewalls and having the lengths of the headers horizontal, pipesconnecting the headers, flanged supports extending across the spacebetween the walls and resting at their ends upon the headers and roofingfor the space above the headers resting upon the flanges of the supportsand giving room for circulation of hot gases between the pipes and theroofing.

LEON T. MART

